1. Field of the Invention
This invention relates to a driver assist device for an industrial truck and to an industrial truck incorporating the driver assist device. In particular, the invention relates to a driver assist device for an industrial truck which, when located on an industrial truck, projects a lighting effect on the roadway.
2. Technical Considerations
It is known that a wide range of vehicles, e.g. buses, motor homes and trucks, can be equipped with a camera system to provide the driver with an overview during materials handling operations that is difficult or even impossible to achieve by means of mirrors or by direct sight. The use of camera systems on industrial trucks, in particular on counterbalance fork-lift trucks, is also known. DE 10 2007 063 226 A1 describes the superimposition of an image of the potential path of the vehicle (as a function of a steering angle) on the display of a camera image to indicate whether, at a particular steering angle, a potential obstacle is located in the path of the vehicle.
One disadvantage of this method of the known art is that the display from the camera does not provide a three-dimensional impression but only a significantly smaller image of the roadway and, therefore, is helpful only to a limited extent when approaching a position in a warehouse.
A typical problem that occurs very frequently in working with industrial trucks is that a significant distance must first be traveled to reach a warehouse position, and the industrial truck must be turned by 90° immediately in front of the warehouse position to orient the load handling means, such as a load fork, to the warehouse position or to a load that is stored there. The most frequent situation of this type is when loads are being picked up or set down on shelf systems using counterbalanced fork-lift trucks or reach trucks. In this case, the driver drives the vehicle along the shelf aisle until the vehicle is immediately in front of the warehouse position where the materials handling operation is to be performed. The driver must then turn the industrial truck by 90° with respect to the previous direction of travel to orient the load fork to the position of the shelf or the load. During this rotation, the driver must be able, on the basis of his or her own routine and experience, to orient the fork tines of the load fork so that they can be inserted into the corresponding openings of the pallet on which the load is stored at a particular location in the warehouse. If the vehicle is at an offset with respect to these openings and possible corrections, e.g. by means of a sideshifter device for the load forks, are not sufficient, the orientation must be corrected, if necessary by multiple maneuvers of the truck. This correction wastes time and so far can only be minimized and avoided by ensuring that the driver has enough practice and experience to efficiently correct the vehicle position.
DE 10 2006 002 960 A1 describes an industrial truck with an optical warning device in which a lighting effect that points in the direction of travel is projected onto the roadway to warn people in the vicinity of the approach of the industrial truck. However, this method serves only to warn against an approaching industrial truck and does not offer any assistance during maneuvering of the truck and the rolling on or off of a warehouse item.
Therefore, an object of the invention is to provide a driver assist device for an industrial truck as well as an industrial truck and a system with which it is possible to more easily and accurately approach a warehouse position on a curve and to eliminate the disadvantages described above.